PHP 随机查询

Question

我已经成功地随机化了我的测验，但我现在面临的问题是，即使已经回答了某些问题，也会再次显示。我还有一个限制将从数据库中检索的问题的问题。我想让问题在测验中只随机显示一次，并且只从数据库中选择 5 个问题作为示例。

$singleSql = mysql_query("SELECT * FROM questions ORDER BY RAND() LIMIT 1");    
    while ($row = mysql_fetch_array($singleSql)) 
    {
        $id = $row['id'];
        $thisQuestion = $row['question'];
        $question_id = $row['question_id'];
        $q = '<h2>'.$thisQuestion.'</h2>';


        $sql2 = mysql_query("SELECT * FROM answers where question_id = '$question_id' ORDER BY rand()");
        while($row2 = mysql_fetch_array($sql2))
        {
            $answer = $row2['answer'];  
            $correct = $row2['correct'];                
            $answers .= 
            '<label style="cursor:pointer;"><input type="radio" name="rads" value="'.$correct.'">'.$answer.'</label>
            <input type="hidden" id="qid" value="'.$id.'" name="qid"><br /><br />';
        }
    }

Answer 1

使用join。不需要两个不同的查询

SELECT * FROM questions q join answers a
on q.question_id=a.question_id
ORDER BY RAND() LIMIT 1